I need to know about humidity.

I have a Hygrotherm and Reptifogger, and I have the Reptifogger plugged into the Hygrotherm so that it stays at 75, but I don't know what humidity it should be. My snake still shed in pieces. There's condensation on the left side of the tank, and the substrate in the middle is wet. I just don't know how to get it optimal. I read it should be at 70% humidity to be optimal, and raised when shedding. I've been keeping it from 70%-80% when she last shed, but I don't think it's doing too many favors.. :(

If your setup still has a open screen top the fogger can be set to 90 but the fog escapes and does not actually create the humidity you need. You need to have the screen mostly covered so the humidity is trapped.

The wet substrate is probably from the fogger hose dripping. The hose gets water vapor collected inside and starts to drip. When I used a fogger for my brb I placed moss under the hose to help soak up the water and help humidity.

A fogger can also be like a tstat. Just because you set it to a certain number does not mean it will create that set value, it can be lower or higher. You need a good humidity gauge and play with the setting until it starts creating the environment you need.

It also sounds like your snake could use a humid hide. I have a 40 gallon tank that is hard to keep high humidity. I use moss in both hides and must it every few days during regular time and keep it damp during shed times. Using that really helped and gives my snake great sheds. I also mist the cage still but nothing like I did before, now it is mainly for the plants.

As always a pic of your setup could really help and may allow for us to give you more or better advise. Like the condensation on the left side is probably from the hose position but I really can't give any tips without knowing for sure.